Thus, this clinical trial is being conducted to evaluate the antihypertensive effect and safety of a fixed-dose combination (FDC) drug of 2 antihypertensive agents with different pharmacological effects, telmisartan 80 mg and amlodipine 5 mg (T80/A5 mg), compared with telmisartan 80 mg (T80 mg) monotherapy in Japanese patients with essential hypertension who fail to respond adequately to treatment with the maximum dose of telmisartan 80 mg monotherapy. In this trial, a multi-centre, randomised, double-blind, double-dummy, active-controlled, parallel group comparison method is employed.